How to embed a qwindow into qmainwindow

nathanday89

This is the main.cpp file for the basic shapes 3D example.

int main(int argc, char **argv)
{
    QApplication app(argc, argv);
    Window *view = new Window();
    QWidget *container = QWidget::createWindowContainer(view);
    QSize screenSize = view->screen()->size();
    container->setMinimumSize(QSize(200, 100));
    container->setMaximumSize(screenSize);

    QWidget *widget = new QWidget;
    QHBoxLayout *hLayout = new QHBoxLayout(widget);
    QVBoxLayout *vLayout = new QVBoxLayout();
    vLayout->setAlignment(Qt::AlignTop);
    hLayout->addWidget(container, 1);
    hLayout->addLayout(vLayout);

    widget->setWindowTitle(QStringLiteral("Basic shapes"));

    Qt3D::QAspectEngine engine;
    engine.registerAspect(new Qt3D::QRenderAspect());
    Qt3D::QInputAspect *input = new Qt3D::QInputAspect;
    engine.registerAspect(input);
    engine.initialize();
    QVariantMap data;
    data.insert(QStringLiteral("surface"), QVariant::fromValue(static_cast<QSurface *>(view)));
    data.insert(QStringLiteral("eventSource"), QVariant::fromValue(view));
    engine.setData(data);

    // Root entity
    Qt3D::QEntity *rootEntity = new Qt3D::QEntity();

    // Camera
    Qt3D::QCamera *cameraEntity = new Qt3D::QCamera(rootEntity);
    cameraEntity->setObjectName(QStringLiteral("cameraEntity"));

    cameraEntity->lens()->setPerspectiveProjection(45.0f, 16.0f/9.0f, 0.1f, 1000.0f);
    cameraEntity->setPosition(QVector3D(0, 0, -20.0f));
    cameraEntity->setUpVector(QVector3D(0, 1, 0));
    cameraEntity->setViewCenter(QVector3D(0, 0, 0));
    input->setCamera(cameraEntity);

    // FrameGraph
    Qt3D::QFrameGraph *frameGraph = new Qt3D::QFrameGraph();
    Qt3D::QForwardRenderer *forwardRenderer = new Qt3D::QForwardRenderer();

    forwardRenderer->setCamera(cameraEntity);
    forwardRenderer->setClearColor(QColor(QRgb(0x4d4d4f)));
    frameGraph->setActiveFrameGraph(forwardRenderer);

    // Setting the FrameGraph
    rootEntity->addComponent(frameGraph);

    // Scenemodifier
    SceneModifier *modifier = new SceneModifier(rootEntity);

    // Set root object of the scene
    engine.setRootEntity(rootEntity);

    // Create control widgets
    QCommandLinkButton *info = new QCommandLinkButton();
    info->setText(QStringLiteral("Qt3D ready-made meshes"));
    info->setDescription(QStringLiteral("Qt3D provides several ready-made meshes, like torus, cylinder, cube and sphere."));
    info->setIconSize(QSize(0,0));

    QCheckBox *torusCB = new QCheckBox(widget);
    torusCB->setChecked(true);
    torusCB->setText(QStringLiteral("Torus"));

    QCheckBox *cylinderCB = new QCheckBox(widget);
    cylinderCB->setChecked(true);
    cylinderCB->setText(QStringLiteral("Cylinder"));

    QCheckBox *cuboidCB = new QCheckBox(widget);
    cuboidCB->setChecked(true);
    cuboidCB->setText(QStringLiteral("Cuboid"));

    QCheckBox *sphereCB = new QCheckBox(widget);
    sphereCB->setChecked(true);
    sphereCB->setText(QStringLiteral("Sphere"));

    vLayout->addWidget(info);
    vLayout->addWidget(torusCB);
    vLayout->addWidget(cylinderCB);
    vLayout->addWidget(cuboidCB);
    vLayout->addWidget(sphereCB);

    QObject::connect(torusCB, &QCheckBox::stateChanged,
                     modifier, &SceneModifier::enableTorus);
    QObject::connect(cylinderCB, &QCheckBox::stateChanged,
                     modifier, &SceneModifier::enableCylinder);
    QObject::connect(cuboidCB, &QCheckBox::stateChanged,
                     modifier, &SceneModifier::enableCuboid);
    QObject::connect(sphereCB, &QCheckBox::stateChanged,
                     modifier, &SceneModifier::enableSphere);

    torusCB->setChecked(true);
    cylinderCB->setChecked(true);
    cuboidCB->setChecked(true);
    sphereCB->setChecked(true);

    // Show window
    widget->show();
    widget->resize(1200, 800);

    // Update the aspect ratio
    QSize widgetSize =  container->size();
    float aspectRatio = float(widgetSize.width()) / float(widgetSize.height());
    cameraEntity->lens()->setPerspectiveProjection(45.0f, aspectRatio, 0.1f, 1000.0f);

    return app.exec();
}

MainWindow.cpp

What I want to do is create a ui where I create my own check boxes and embed the 3D rendering in an existing QWidget that I've placed in my mainwindow.ui (figure 1).

Figure 1
0_1547586174593_3bcff2ea-250f-4150-a47f-15f7306cb9de-image.png

Here is the code that I used to do this:

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    QWindow *view = new QWindow();
    QWidget *container = QWidget::createWindowContainer(view);
    container->setParent(ui->windowWidget);
    container->setMaximumSize(ui->windowWidget->size());

    Qt3D::QAspectEngine engine;
    engine.registerAspect(new Qt3D::QRenderAspect());
    Qt3D::QInputAspect *input = new Qt3D::QInputAspect;
    engine.registerAspect(input);
    engine.initialize();
    QVariantMap data;
    data.insert(QStringLiteral("surface"), QVariant::fromValue(static_cast<QSurface *>(view)));
    data.insert(QStringLiteral("eventSource"), QVariant::fromValue(view));
    engine.setData(data);

    // Root entity
    Qt3D::QEntity *rootEntity = new Qt3D::QEntity();

    // Camera
    Qt3D::QCamera *cameraEntity = new Qt3D::QCamera(rootEntity);
    cameraEntity->setObjectName(QStringLiteral("cameraEntity"));

    cameraEntity->lens()->setPerspectiveProjection(45.0f, 16.0f/9.0f, 0.1f, 1000.0f);
    cameraEntity->setPosition(QVector3D(0, 0, -20.0f));
    cameraEntity->setUpVector(QVector3D(0, 1, 0));
    cameraEntity->setViewCenter(QVector3D(0, 0, 0));
    input->setCamera(cameraEntity);

    // FrameGraph
    Qt3D::QFrameGraph *frameGraph = new Qt3D::QFrameGraph();
    Qt3D::QForwardRenderer *forwardRenderer = new Qt3D::QForwardRenderer();

    forwardRenderer->setCamera(cameraEntity);
    forwardRenderer->setClearColor(QColor(QRgb(0x4d4d4f)));
    frameGraph->setActiveFrameGraph(forwardRenderer);

    // Setting the FrameGraph
    rootEntity->addComponent(frameGraph);

    // Scenemodifier
    SceneModifier *modifier = new SceneModifier(rootEntity);

    QCheckBox *torusCB = ui->torusCB;
    QCheckBox *cylinderCB = ui->cylinderCB;
    QCheckBox *sphereCB = ui->sphereCB;
    QCheckBox *cuboidCB = ui->cuboidCB;

    torusCB->setChecked(true);
    cylinderCB->setChecked(true);
    cuboidCB->setChecked(true);
    sphereCB->setChecked(true);

    QObject::connect(torusCB, &QCheckBox::stateChanged,
                     modifier, &SceneModifier::enableTorus);
    QObject::connect(cylinderCB, &QCheckBox::stateChanged,
                     modifier, &SceneModifier::enableCylinder);
    QObject::connect(cuboidCB, &QCheckBox::stateChanged,
                     modifier, &SceneModifier::enableCuboid);
    QObject::connect(sphereCB, &QCheckBox::stateChanged,
                     modifier, &SceneModifier::enableSphere);

    // Set root object of the scene
    engine.setRootEntity(rootEntity);


    // Update the aspect ratio
    QSize widgetSize =  container->size();
    float aspectRatio = float(widgetSize.width()) / float(widgetSize.height());
    cameraEntity->lens()->setPerspectiveProjection(45.0f, aspectRatio, 0.1f, 1000.0f);
}

MainWindow::~MainWindow()
{
    delete ui;
}

Here's my main function:

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}

What I end up with is this:

0_1547586435409_f1c46cd9-e0b7-4b12-aadb-f3af0457f1bf-image.png

I don't get the 3D rendering to show up. How would I go about fixing this? I thought that all I would need to do is change the parent of my window container to the Qwidget I have set up on my UI.

SGaist

Hi and welcome to devnet,

What version of Qt are you using ?
On what version of Ubuntu ?

nathanday89

I'm using Qt 5.10 on Ubuntu 14.04

SGaist

Can you test a more recent version of Qt ?
Do you also get that if you use your distribution provided Qt ?

JKSH

@nathanday89, does the unmodified Basic Shapes example work for you?

nathanday89

@JKSH Yes, the unmodified example works for me. I just want to embed the window that pops up inside a Qwidget in my mainwindow.ui instead of it opening a window of its own.

SGaist

What about running your code using your distribution provided Qt ?

JKSH

@nathanday89 said in How to embed a qwindow into qmainwindow:

Yes, the unmodified example works for me. I just want to embed the window that pops up inside a Qwidget in my mainwindow.ui instead of it opening a window of its own.

Then you have just made a mistake while copying+pasting the code. Your original post contained Window *view = new Window(); -- this line does not exist in the Basic Shapes example.

I recommend you make a copy of the original Basic Shapes project and gradually insert your own code into it.

The first thing to try is replace the code that shows the top-level widget with your own QMainWindow:

/* (Original code)
    
    // Show window
    widget->show();
    widget->resize(1200, 800);
*/

// (Replacement code)
QMainWindow myWindow;
myWindow.setCentralWidget(widget);
myWindow.show()